There's been a backlash against 3D of late. Television manufacturers - LG aside - focused on anything but 3D at this year's CES trade show in Las Vegas. Higher resolutions and smart TV capabilities were of a greater priority to most and stereoscopic video viewing on TVs seems to have been relegated to just another feature, carrying as much marketing weight as other former, more popular terminology like screen refresh rates and virtual surround sound.

The format is still thriving in cinemas, however. It's getting bums on seats (for our American chums, that means "bottoms" not "hobos"). And 3D movies are said to make more money at box office than their 2D counterparts.

So the studios have a dilemma: it makes financial sense to continue to make 3D movies for the cinema, but the market for 3D in the home has never really taken off as expected. And manufacturer indifference doesn't help.

The answer, then, according to some, is to get more content on to the shelves. The more 3D Blu-rays available, the more likely the adoption. And whether you agree with the philosophy or not, that includes 2D to 3D conversion of back-catalogue classics.

It's part of Fox's strategy certainly. Like many of its peers, the studio is in the process of converting some of its most popular movies to 3D. However, unlike rivals, it's also taken the bold step of skipping cinematic release on some and converting them for home use only.

So as part of the release of the Blu-ray 3D of I, Robot, its first such title, Fox invited Pocket-lint to 20th Century Fox Home Entertainment at Fox Studios in Century City, Los Angeles, to meet the team behind its conversion from Alex Proyas's 2D original to full stereoscopic 3D.

What sets this particular project apart from the big-screen 3D adaptations currently being undertaken or screened - such as Fox's own Titanic and Independence Day - is that the studio has decided to convert a "handful" of titles to 1080p 3D only.

This resolution restriction means they will be Blu-ray 3D exclusives. And, as the process is not intended to create masters for cinematic release, it is cheaper and more accessible. Or, at least, that was the initial idea - it was a process that eventually forced both Fox and its partner in the project, JVC, to create all-new dedicated equipment.

With I, Robot, the Fox team chose its first candidate to undergo the procedure well. Watching through certain scenes of the Blu-ray 3D edition you'd swear blind that it was intended for the format in the first place. There are so many shots that invoke visual depth that it feels layered even in 2D. One, in which robot Sonny leaps through a smashed window towards the camera, is straight from the 3D action film handbook. It's an ideal sequence to illustrate how the new part-automated JVC system works.

A rough roto is mapped onto the frames to start

The JVC conversion tools don't require as much rotoscoping of each scene as other systems, in that it will automatically render three-dimensional depth when just a few forward or back elements have been identified. And that saves a lot of time and, therefore, money.

"The reason why we use the JVC tool is we don’t need as much roto as with other systems," Pocket-lint was told by Ian Harvey, senior vice-president of advanced technology at Fox.

"We look at the movie, we look at all the scenes and we pick out how we want the movie to look. So we basically create a depth script. We create something that describes how we want the movie to look.

"That depth script then says, ‘These items need to be moved forward, these items need to be moved back.’ We have to identify the items in each shot that are going to provide depth. So the first thing we do in the example scene is we say Sonny is going to be forward, that room behind the window needs to be back. We need to identify Sonny and we need to identify the room, the hole."

A rough roto map is created for each frame, followed by individual, detailed roto masks for each of the different elements. The JVC system then positions the objects into a depth map for the whole scene, automatically creating depth in other areas of the frame, and what would normally take a lot of man hours of manual work is completed in much less time.

There are other technological aids that can cut manual work loads too.

"To create the left eye and the right eye, for 3D, the system shifts the masks to create two images," Harvey explained. "But as soon as we shift that mask, there's missing information. So we have to create that information.

"There's many ways to do that. One of which is 'painting', where somebody literally has to go in and paint each frame by hand to create that extra information. But one of the benefits of the JVC tools is that their algorithms give us a great way of creating that data that normally has to be created by hand.

"When it gets down to the efficiency of the process - the manual portions of it - we reduce the amount of roto and the paint, where somebody goes in and literally paints, are dramatically reduced."

Note the distortion around Sonny's leg that needs to be manually altered

That's not to say there isn't a need for a manual operator or digital artist. On the next shot of the sequence, Sonny leaps away from the building and we see him from behind. And it is here that the new computer system can introduce anomalies that need to be corrected by hand.

When the system fills in the information it thinks should be in the frame for each eye, it can introduce distortion. In the sequence, this was evidenced by a wobbly line by the lead character's knee. An artist is required to go in and fix that and similar foibles.

However, this is a far quicker process than originally having to do it all by hand, so is a tolerable side effect.

The benefit of using such a system is obvious. Although it cost a small fortune to set up for the first time, the studio set-up can now be used to convert other films at the fraction of the cost. And as the output is just 1080p, the conversion process doesn't have to stand up to the gaze of an IMAX crowd.

That's not to say Fox will now just churn through its entire library for the sake of it. We were told that it will be used only on suitable movies, such as I, Robot - ones that lend themselves well to the process and are commercial enough to be a success in retail. That translates at present to the aforementioned "handful".

Sadly, neither Harvey nor other senior executives would let on exactly which films are now in the process of following I, Robot 3D's lead. But considering the final result, who's to say that there isn't a healthy future for 3D in the home yet?

I, Robot 3D is available on Blu-ray 3D now.

What other films from Fox's back catalogue would you like to see converted? Die Hard? Let us know in the comments below.